


Untimely Thirst

by EtoileVoidGalaxia



Category: Transformers: Prime
Genre: Alternate Universe - Fantasy, Alternate Universe - Vampire, Alternate Universe - Werecreatures, M/M, Mutual Pining, My first Megop fic, Not Beta Read, Pining, Pining Idiots, Vampire!Optimus, Werewolf!Megatron
Language: English
Status: Completed
Published: 2020-12-05
Updated: 2020-12-05
Packaged: 2021-03-10 01:46:53
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 3,009
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27886225
Author URL: https://archiveofourown.org/users/EtoileVoidGalaxia/pseuds/EtoileVoidGalaxia
Summary: Trapped in a collapsed energon mine with Megatron, Optimus is struck with the need to drink energon. With a wagging tail, Megatron tries to convince Optimus to drink from his lines, and Optimus attempts to hold out until they are saved. Note: attempts.
Relationships: Megatron/Optimus Prime
Comments: 4
Kudos: 38





	Untimely Thirst

**Author's Note:**

> This is my first (and maybe only) MegOp fanfiction. I am not a MegOp shipper- I don't mind it, and I find it very cute at times, but I am not actively shipping it, so please take this with a grain of salt. 
> 
> This was done because pple on tumblr wanted a MegOp Vampire x Werewolf au and I wanted the monster-formers, so here we are. 
> 
> There may be a few suggestive parts...? Just a word of warning.
> 
> That's all, please enjoy!

Looking back on it, Optimus should **not** have jumped right back into battle after nearly getting his aft handed to him by those monster hunters. He most certainly **should** have taken heed of Ratchet’s warnings and even more so, he should have taken something to drink. 

Although the humans have expressed their interest and lack of fear from the fact that Optimus is basically a “space vampire” he still did not want them to learn about some of the other aspects that come with a pair of fangs. He is much more than a glorified bat— he can’t even turn into a bat! He couldn’t exactly blame them of course, their encounters with his kind were often quick and without explanation, so humans had to make up some information to explain the event to themselves. Whatever the case, he would much rather listen to Miko ask for the hundredth time if he would turn into a bat than be in _this_ predicament.

A fight in an energon mine was something that did not often end up well, this was no exception. Too many shots deflected from themselves instead hit the walls or pillars of the cave, and now they were stuck, an enclosure far too cramped to fight in, but large enough that they could at least sit apart like civilized mechs. They _were_ able to stand before, but between their attempts at fighting and the attempts of blasting a hole to escape, they were forced to sit together and wait for help to arrive. 

Meanwhile, Megatron fared arguably worse, at least in his own eyes. Optimus showed no sign of his predicament, while Megatron was forced to display it before himself. During the fight he had intended to utilize his own extra ability, termed “werewolf” by humans. Aeons fighting as a gladiator allowed him to regulate his transformation, meaning he could hang in a range between his usual form and going for a full wolf, but something about Unicron’s blood affected his transformation. It took much longer to return to normal and unless he wished to walk around with dog ears and a tail he rarely turned. Today however, was a fight against Optimus. He brought his all to every match as he always did, and as a consequence, he sat in this enclosed place with Optimus trying desperately to hide his furiously wagging tail. It didn’t help that his scent filled their little room, only making his tail wag faster, and his ears twitch as he longed to rest them upon his chassis to listen to the soft thrum of his spark.

Both with their own hardships to hide, they sat, silently. Awkwardly. It was going to stay that way until they were saved. Correction- it was _supposed_ to stay that way until they were saved. Optimus’ needs, however, did not relent and weighed down on him heavier than the stones above their helm. In his unwilling observations of Optimus his hardships did not go unnoticed by Megatron. The way his frame rattled as he shook, and his labored ex-venting, that caused him to flare his fangs. Not to mention the unnaturally brighter glow of his optics. In the same way Orion would have his occasional hunger pangs, Optimus, despite being a prime, still craved. Without thinking, Megatron spoke up.

“Do you need a drink?” 

He even offered his arm. It hung there a moment, while Optimus’ jaw remained in his lap. Megatron did not fare much better than a series of “ah, um, well” spilling from his vocalizer in the same fashion Starscream did when he was seriously considering the pros and cons of tearing off his wings. Or more horrifyingly, the same string of noises Orion made when he first offered his energon for him to drink. 

It took a moment for Optimus to regain his senses. Of all the things to happen that was not one of them. It took the feeling of fluids dribbling from the corners of his mouth for him to snap it shut, and consequently snap his mask on right after it.

“No.” It was flat. Bitter. Fake. His usual response, his usual demeanor against his enemy. The dance they both knew for so long. Megatron could work with this.

“Why Prime?” he grinned, lopsided and cocky, flashing his own sharpened denta and trying to ignore how his tail seemed to pick up the pace. “Afraid I may stab you in the back? As we’ve already confirmed we cannot do that here. After all, it is your denta in my lines. If I tried anything too suspicious for you you could easily drain me. No?”

His heating fans kicked in. A loud roar amidst the silent little cavern they were stuck in, and a louder roar in Megatron’s ears. He couldn’t help it though, he did want to taste Megatron’s energon again. It was sweet, intoxicatingly so, and even more so after a battle. He could drink it for hours if he was allowed to, but that would mean that he’d hurt his friend, and in the past that’s what inevitably stopped him. Now, however, that barrier was worn down. He had no qualms about punching him, shooting at him, or even attempting to sheath his blades in his chassis. It did not however mean that he wanted him dead. No, he only wanted him back. Aeons of war and he still thought in that same foolish way he did as an archivist. Ratchet was right, he did go soft. 

“I do not want or need your energon Megatron,” he lied, staring him straight in the eye as he did. “Even if I did, it’s tainted.” 

That was true. Dark energon pulsed along with his usual energon intake, and for the first time in a long time, Megatron cursed Unicron’s blood. He didn’t have any feasible reason to convince Optimus to drink his energon. Tainted now with dark energon, his own energon must have smelled disgusting. It must have seemed revolting. At the very least he did not have to worry about his wagging tail anymore.

“It’s not like you have much of a choice.” It felt like an excuse— one he was trying to tell himself rather than Optimus. “By the way you sound, I doubt you would be able to hold up until any help arrives, yours and mine.” He leaned back smirking as he was once more granted the upper hand. “Even if you do, how hungry would you be by then? What would you do if it was your precious medic that came around? Or perhaps the scout Bumblebee? Would you drain them at first glance?” He bit his glossia then forcing his train of thought to a halt before he began to spill too much.

That… That was a good excuse to drink from Megatron’s lines again. Dark energon or not, Optimus craved to sink his denta into his proto-mass again. To relish in the taste of energon pouring down his throat directly from Megatron’s lines. It always felt as if it was being pumped right to his awaiting glossia when he drank it right after Megatron came back from a battle. Sure, Ratchet’s energon tasted nice as well, but nothing seemed to beat the sweet flavor he got from Megatron. It took a lot of willpower just to keep himself from revving his engines, a bad habit that occurred when he got excited, carried on from his life as Orion pax. One that Megatron would most certainly notice and recognize. As much as he wanted to— as much as he craved it, he still refused to drop his guard. Why was Megatron so intent on supplying him energon anyways?

“Why...Why do you want me... to drink from you?” he managed through heavy ex-vents. It was getting bad. Incredibly bad. 

It was most certainly getting bad. Caught red handed for something he did not think about. For all his planning and consideration to convince Optimus to drink from him, he never managed to formulate a feasible excuse. For now, at least, he had to buy time. 

“Why indeed,” he wondered aloud, forcing his face into a sly grin. He allowed himself a pause to consider his next words carefully, cautious to save a part of his processor to regulate his face. “Perhaps it is to ensure that none of my troops are felled by your fangs.” That sounded… okay… right?

Apparently it did not as Optimus arched an optical ridge. “I was unaware you still cared for your crew, considering you did not raise a digit to aid them as the mine collapsed.” Right. There were most certainly a good number of Vehicons that may be caught in the rubble, and Megatron was far too preoccupied fighting Optimus to care. Optimus on the other hand did his best to ensure his team was safe, even amidst fighting him.

He chuckled at the comment and smirked, a look that irked and irritated Optimus. Just let him suffer in peace already. The more this dragged on the more he could feel his defenses wear down. “Well, Prime, perhaps I wanted to see you succumb to your… oh, what was it called again?” No. He knew well what it was called and he refused. “I recall Orion talking all about it once… ah yes, an energon frenzy, wasn’t it?” If he was in that state, he could rip him apart. Turn feral with barely a twitch of an optic. Of course that was what Megatron wanted. Force him to fight on his level. Like a gladiator, only concerned for their own life. Like a monster, without thinking. It made his lines run cold.

Perhaps he overstepped his bounds. Optimus was no longer trembling, his armor instead clamping around his frame. Even his auditals which Megatron had taken to watching twitch back and forth while Optimus wasn’t looking now froze in place before they lowered in the same manner he would flatten his ears against his helm. The only remaining reminder of his hunger was in the burn of his optics, now glowing far brighter than it did before, the bright beams focused right on him in a hateful glare. A spotlight for him and him alone, and one he was used to returning with a smile.

They glared at one another, a glare that any from their own teams would be interpreted as hateful glares, seeking to eagerly claw out one another’s optics if only the situation had been better. Instead, two masks faced one another—

_I want to drink Megatron’s energon!_

_I want Optimus to drink my energon!_

—both hiding the same thing.

They sat there for a few more minutes, glaring before the tremors returned. They were barely noticeable at first if not for the aid of Megatron’s heightened hearing. Slowly that grin became real. He grew eager awaiting Optimus’ inevitable unravel before him. Simultaneously, Optimus’ scowl, revealed once his battle mask snapped back from the increasing tremors, became more real as well. He did not wish to succumb to Megatron’s wishes, but more so, he did not want to end up sucking Megatron dry.

The tremors increased, and the haze was beginning to seep into his processor. Everything smelled so heavily of energon— likely because they were in a collapsed energon mine— but it smelled specifically of Megatron’s energon. His spark spun in his chest as the dizzying urge overtook his processor, crawling over his shielding walls and forcing his optics to snap away. To look away, to look anywhere else but at Megatron.

He leaned onto his servos now, mouth opening and closing as he panted, showing off his denta glowing red as they were caught in the spotlight of his optics. He was only vaguely aware of his wagging tail as he watched Optimus come undone. It took a tremendous amount of willpower to keep himself from bending as well, he wanted Optimus to ask him, but if it took any longer…

“Megatron.” He sounded so strangely weak despite the bright intensity of his optics. “May I drink your energon?”

There’s drool slipping past his fangs, dripping down his chin and onto the floor, but he cannot find the will inside himself to care. He’s so, so thirsty, and while any energon would suffice at this point, he doesn’t want anyone else’s. Even if help were to arrive, just in the bare nick of time, both the Autobots and the Decepticons would have to pry him from Megatron. Even though Megatron offered first, it still comes as a surprise when he immediately raises his arm before him. Optimus is only vaguely aware of the soft and subtle thump as Megatron’s tail hits the ground in it’s furious wagging, but he doesn’t have the mind to process such or to even care. He traces the seams in his armor, mostly the same since he last drank from him, and he opens his mouth to sink his fangs into the proto-flesh at one of the seams. 

Dark energon is strangely sweet, but it’s a fake candy-like flavor that is easily distinguished from Megatron’s own energon. It’s every bit as intoxicating as he remembered long ago sweet, but now a degree of something savory was so much clearer now, whether this was enhanced by the dark energon, or time and aging, he may never know. Whatever the case, he greedily drank what his energon lines pumped onto his tongue, savoring every drop, knowing it may be many more aeons before he was granted another taste.

Megatron’s tail hit the ground so harshly that it was beginning to hurt. The bite on the other hand felt blissful, painless, and as wonderful as it did long ago. The sheer trust needed to offer someone like Optimus in order to make sure they were not drained of their energon, was not lost upon him. As much as the idea mixed with the ongoing war made his tanks twist into knots, he shoved them to the back of his processor. He’d use it as an excuse later. A reason why he most certainly did not indulge in such a… close encounter. For now Megatron let himself feel his energon flow into Optimus. A piece of himself being given to Optimus. Romantic, in some incredibly twisted sense, befitting for the two of them. Miraculously, even though Optimus was drinking Dark energon, it did not take any visible effect. 

It would take a while for Dark Energon to properly settle in his energon lines. An upside to being a “space vampire” his resistance to foreign energons was much higher and with the added aid of the matrix, the two seemed to cancel each other out. Meaning he could continue to drink for just a little longer. He could take another sip of his fallen friend’s energon. He could savor another taste of Megatron. He was deaf to everything but the slow thrum of his energon lines and his spark. He wanted more— he wanted it all. Greedily he kept drinking and drinking, becoming more and more lost. A energon frenzy was approaching, he could feel it, feel it dribble into his consciousness, but this was what Megatron wanted to see wasn’t it? If Megatron wanted to see him delve into madness the same way he did for dark energon, he was more than willing to put on a show, more than willing to show off because he—

“Orion.” It was a soft whisper, strained as Megatron glared with tired optics.

Otpimus tore himself from his enemy’s arm checking internally for his energon levels and most importantly dark energon levels. It was close. If he drank any more, he may have actually begun to have some problems. It was diluted with regular energon, something that likely aided the slow intake. Optimus spared a worried glance to Megatron, who’s smirk seemed much more forced now that he could focus on it. The wagging tail and twitching ears became quickly apparent as well and just before Optimus could ask him about it, Megatron beat him to the punch.

“No, energon frenzy? Funny seeing as you were just about to drink me dry.” He chuckled earning a scowl from Optimus.

In that moment, a stone was shoved aside, revealing a beam of light other than their red and blue ones. A breath of fresh air seeped in through the hole, washing away the scent of energon, and each other. 

“Optimus! Are you okay there?”

“Just fine, Bulkhead.”

More rocks were scooped away, and the two war leaders stumbled out into the excavated cavern. Optimus wavered his audital fins still twitching as he felt the tendrils of that energon frenzy seep into him, already draining his mental energy as he fought against it. Megatron fared no better having been literally drained, as he was taken aside by Soundwave Bulkhead scowled giving a stiff nod to the silent mech who returned the nod before they parted ways, their leaders in tow.

“Sorry Prime, I had to team up with him to get you out…” Bulkhead muttered as if it was a horrible act. 

“In... the moment it was a wise choice Bulkhead…. I… I appreciate your efforts.” He managed to mumble as a ground bridge opened up. The swirling colors made him dizzy and irritated, but he forced himself to keep quiet about it.

“You sure you were okay with bucket head?” It took him a moment, recalling Miko having coined the name after Megatron and his helm’s likeness to a bucket.

He considered his choices in what to say, taking care to avoid the truth, overthinking it immensely as he settled on, “it was fine.”

“Ratchet’s got some energon for you when you get back to base, just hold on a little longer Prime” Optimus barely managed to hide his grin, tuning away just in time to see Megatron disappear in his own ground bridge a safe distance away.

“It’s alright Bulkhead. I’ve had my fill.”

Now, if only he took the chance to pet him.

**Author's Note:**

> If you noticed some errors in the fic plz tell me. I didn't really edit it, because I was feeling lazy. Sorry and thank you! 
> 
> Comments would be much appreciated!


End file.
